This inventions relates to boom mower attachments for tractors and, more particularly, to a curing head operable at varying distances and angles from the line of travel of the tractor to which it is attached.
It is well known to use a cutting head attached to a tractor by means of an articulated boom to mow gross and other vegetation along roads, railroad rights-of-way and the like. Such arrangements have been described, for example, in U.S. Pat. No. 5,210,997, U.S. Pat. No. 4,887,417 and U.S. Pat. No. 4,869,417. The articulated booms have generally been attached to the side of the tractor, as shown, for example, in U.S. Pat. No. 5,210,997, or to the rear as shown in U.S. Pat. No. 4,887,417. As is best illustrated in U.S. Pat. No. 5,210,997, such devices have often provided for movement through a wide range of angles in the plane normal to the line of travel of the tractor in order to cut over obstacles such as guard rails and also either to conform the plane of operation of the cutting head to the slope of the ground or to rotate the cutting head up for cutting tree branches and the like. However, prior devices have permitted the cutting head to move out of the plane normal to the line of travel of the tractor only when a tree or other obstruction has been struck (breakaway action) or when the cutting head is not in use. The restriction of operation to the plane normal to the line of travel of the tractor makes it difficult or impossible to bring the cutting head close enough to the tractor to cut inside the line of travel of the tractor wheels. As a result, when such a device is used to cut gross near the edge of a road, the tractor must be driven toward the center of the road, thus endangering the operator and other motorists.